Listeria endocarditis

ObjectivesTo compare the inhibitory properties of a standard potassium acetate and diacetate blend (Provian K) and a natural fermented and neutralized dry vinegar product (Provian NDV)on the growth of both Listeria monocytogenes and lactic acid bacteria in cured RTE meats.Materials and MethodsFive treatments of cured deli-style ham (72 to 74% moisture, 1.75 ± 0.1% salt, and pH 6.2 to 6.4, 156 mg/kg sodium nitrite and 547 mg/kg sodium erythorbate)where tested, including a control without antimicrobials and different concentrations of Provian K (0.5 and 0.75%) and Provian NDV (0.5%, 0.65%). Cooked products were surface-inoculated with 3-log10 CFU/g of a cocktail of 5 strains of Listeria monocytogenes (including serotypes 4b, 1/2a and 1/2b) or a mixture of 2 lactic acid bacteria (LAB) strains including Carnobacterium divergens and Leuconostoc mesenteroides, both isolated from spoiled cooked meat products. Inoculated slices (100 g/package) were vacuum-packaged and stored at different temperatures for up to 4 and 8 wk, for LAB and L. monocytogenes, respectively. Triplicate samples per treatment were assayed by enumerating twice on modified Oxford Agar for L. monocytogenes and on Plate Count agar (30°C, 48 h) and APT agar with bromocresol purple (27°C, 48 h) for LAB. The study was conducted twice.ResultsResults on Listeria inhibitionControl Ham supported > 1 log increase of L. monocytogenes at 4 and 2 wk storage at 4°C and 7°C, respectively (Fig. 1). In contrast, hams supplemented with 0.5 or 0.75% Provian K or 0.65% NDV inhibited the Listeria growth for 12 and 8 wk at 4 and 7°C, respectively. Inhibition of Listeria on ham supplemented with 0.5% NDV was further affected by pH and moisture. Ham supplemented with 0.5% Provian NDV in the trial 1 (71.5% moisture, pH 6.2) delayed Listeria for 12 wk storage at 4°C, whereas individual samples of trial 1 (72.9% moisture, pH 6.3) supported growth (> 1 log increase) at 8 wk. Similar trends were observed at 7°C.Results on Lactic Acid Bacteria inhibitionThe Control Ham supported the increase of Lactic acid bacteria to spoilage level (> 6 Logs) at 3 and 2 wk storage at 4°C and 7°C, respectively. In contrast, hams supplemented with 0.5% Provian K or 0.8% Provian NDV showed complete inhibition of LAB for 4 wk. For complete inhibition at 7°C slight higher concentrations of 0.75% and 1% were needed of Provian K and Provian NDV, respectively.ConclusionThe results of this study show the inhibitive effect of a natural fermented vinegar product on the growth of Listeria monocytogenes and Lactic acid bacteria in a cured ready-to eat ham. To have a comparable efficacy with neutralized natural vinegar as with a standard acetate-diacetate product, the dosage of the vinegar based product should be increased by approximately 10%. This can be explained by the lower amount of undissociated acid in the product.

Staphylococcus capitis Endocarditis

Staphylococcus lugdunensis Prosthetic Mitral Valve Endocarditis Complicated by Paravalvular Abscess and Septic Emboli

Progressive rash as the first sign of Listeria meningitis and bacteremia

The influence of commonly used selective agents on the growth of Listeria monocytogenes

Listeria monocytogenes, a ubiquitous foodborne pathogen, was recognized over 70 years ago. It is the source of the human disease listeriosis. The majority of Listeria monocytogenes that have been isolated from food product or human cases are of the serotypes ½ a, ½ b and 4b. Due to the recent outbreaks, recalls and deaths associated with Listeria monocytogenes in ready-to-eat meat products, the United States Department of Agriculture (USDA), Food Safety and Inspection Service (FSIS) on October 2, 2003 issued a directive for the control of Listeria monocytogenes on ready-to-eat products. The ready-to-eat food industry must impose a post-lethality treatment and/or growth inhibitor for Listeria monocytogenes on ready-to-eat products. The purpose of this study was to assess the use of different antimicrobial treatments for the inhibition of Listeria monocytogenes on the surface of food products. The utilization of natural ingredients such as cranberries as well as chemicals such as acidified sodium chlorite was employed. An edible film made of chitosan that was dissolved in acetic acid and lactic acid was also evaluated. The survival of Listeria monocytogenes at freezer temperatures on a variety of ready-to-eat meat products was also assessed. Our study has been successful in understanding the survival of Listeria monocytogenes at freezer temperatures on the surface of ready-to-eat meat products under vacuum and non-vacuum package storage conditions. It has also been observed that the use of cranberry juice, acidified sodium chlorite, and chitosan have great potential antimicrobial properties that can be employed by food processors.

To present and discuss four cases of bilateral endogenous endophthalmitis. An observational study of four patients aged 55-80 years, seen within a 2-year period. All had diagnostic and therapeutic vitrectomy. The antibiotic therapy was guided by analyses of cultures of blood and vitreous. Blood cultures demonstrated Streptococcus pneumoniae in two patients and Staphylococcus aureus and Morganella morganii, each in one patient. The findings corresponded with culture findings from vitreous material in two patients. The primary foci for the metastatic spread of infection were endocarditis, discitis and a subdural abscess of the lumbar spine, urinary tract infection, and infection of a recent hip alloplasty, respectively, in the four patients. Five eyes became blind, whereas three eyes recovered to visual acuity of 0.25-0.67. Endogenous bacterial endophthalmitis usually leads to total loss of vision. The disease is acute and the time span for intervention limited. We believe that an active therapeutic approach including intravitreal antibiotics and vitreoretinal surgery saved three eyes from blindness.

We present a technique for mitral valve (MV) replacement that preserves the anterior mitral leaflet (AML) using complete chordal-sparing mitral valve replacement (CCS-MVR), which maintains the architecture of the left ventricle. This technique is beneficial for patients with functional, degenerative, and infective MV disease who were unable to undergo MV repair. The objective of this study is to ascertain the most efficacious treatment for MV disease. Furthermore, the study will contribute to international guidelines for this procedure and provide data on its efficacy in treating MV disease. We performed MV replacement surgery on 161 patients, maintaining the integrity of the entire subvalvular chordae tendineae apparatus. Of these cases, 92 (57.1%) were degenerative, 58 (36.0%) were functional, 9 (5.6%) were infective, and 2 (1.2%) were rheumatic. Of the 93 patients with complicated MV disease, massive calcification was observed in 59 cases (36.6%) and mitral annular disjunction (MAD) was observed in 25 cases (15.5%) while endocarditis with posterior annular abscess was observed in 9 cases (5.6%). The anterior leaflet is detached from its connection to the annulus along the entire extent from the posterior commissure to the anterior commissure. In cases of excess tissue, a section of the free edge of the translocated leaflet must be removed. This must preserve a small section of the edge and the entire chordae tendineae unit. A CCS-MVR requires 24 to 28 individual sutures in routine cases. The AML was reinserted using 12 to 14 single sutures in this specific order: posterior annulus, posterior mitral leaflet, AML, and prosthetic valve. The 30-day mortality rate was 8.7%, based on 14 cases. Ten patients, representing 5% of the total, required reoperation after the initial procedure. Out of 140 patients,74 (52.8%) experienced LV reverse remodeling at the six-month follow-up. Female patients exhibited a significantly higher rate of LV reverse remodeling (71% vs. 29%, P<0.001) compared to male patients. Patients with mitral annular calcification and MAD demonstrated significantly higher rates of left ventricular reverse remodeling compared to patients with coronary artery disease (CAD). We can conclude with certainty that male gender, CAD, atrial fibrillation, and preoperative left ventricular end-diastolic volume indexed (LVEDVI) are significant predictors of LV remodeling. We found that the median survival time after CCS-MVR was 39.5 months. The results of the multivariable analysis revealed that patients with MAD had significantly worse survival rates than those without. For patients presenting with severely calcified posterior mitral annulus, complicated Barlow disease with MAD, or endocarditis involving the posterior annulus, the AML is consolidated with the posterior mitral leaflet to form a neo-annulus. This procedure is safe and effective for a wide range of simple and complex MV pathologies. Its efficacy is unquestionable. It preserves the complete architecture of the left ventricle, avoiding dilatation and promoting reverse remodeling.

An 88–year–old woman with a history of atrial fibrillation and amoxicillin allergy presented progressive dyspnea. She had been treated in the previous three months for pneumonia and bronchitis. Physical examination revealed basal crackles and a 4/6 systolic murmur. Echocardiography identified mobile vegetations in the mitral and aortic valves (Figure 1), severe mitral regurgitation and leaflet perforation of the mitral valve (Figure 2-3). Laboratory findings included elevated levels of NT–proBNP and fibrinogen. Blood cultures were negative, but valve tissue culture identified Micrococcus luteus, which plausible entered in the bloodstream through a skin or mucosal injury. Empiric antibiotic therapy with ceftriaxone and vancomycin was started. The patient underwent a successful mitral valve replacement with a bioprosthesis and aortic valve shave through endoscopic right minithoracotomy. The postoperative recovery was uneventful, and the patient completed a 6–week antibiotic course. Follow–up echocardiography showed stable prosthesis function and significant symptomatic improvement. This case highlights the evolving microbiology of infective endocarditis associated with gram–positive catalase–positive cocci, typically considered a skin contaminant. Clinicians should recognize Micrococcus luteus as a potential pathogen in susceptible patients and ensure a timely diagnosis and intervention to optimize results.Figure 1 Figure 2 Figure 3

This study describes an application of bacteriocinogenic lactic acid bacteria to improve preservative factors over fish fermentation based on the most frequently used technique in Senegal. Traditional fish fermentation performed by immersion in salted sea water and incubation at 30°C for 24 to 48h to develop flavor, is characterized by a pH value around 7. The process led to the growth of Enterobacteriaceae to reach 9 log CFU/g. Four bacteriocinogenic lactic acid bacteria characterized in previous works were screened for decarboxylation activities. Only cultures of two Lactoccus lactis subsp. lactis (CWBI-B1410 and CWBI-B1426) producing nisin, a heat stable antibacterial peptide, did not produce histamine and tyrosine regarded as undesirable compounds on seafood products. The two lactococcal starter cultures grew well on a substrate based on millet, a local cereal. The AU/ml minimum inhibitory concentration of the antibacterial neutralized supernatant of the bacteriocinogenic starter cultures against Listeria monocytogenes was lower to those of many food poisoning or spoilage bacteria. Then, pieces of lean (Podamassys jubelini) and fat (Arius heudelottii) fish inoculated with 104-5 CFU/g of Listeriamonocytogenes, were immersed in the millet flour based substrate seeded with 105-6 CFU/g pure cultures of the nisinogenic bacteria to evaluate the control of the fermentation at 30°C. Listeria monocytogenes contaminated fish samples immersed in the millet-based substrate without starter cultures addition were used as negative controls. The starter culture fermentation gave the lowest fish pH reading. The pH was dropped and maintained to a final level lower to the minimum value for the growth of many Enterobacteriaceae genera reported in spoiled fish. The growth of Listeria monocytogenes was significantly inhibited by starter cultures compared to that in the negative controls. These results indicate that cultures of the two nisin producers on the new formulated matrix can be used to improve fish fermentation in Senegal.

Queso fresco (QF), a fresh soft cheese, is one of the most popular Hispanic cheeses in the United States and is frequently associated with Listeria monocytogenes outbreaks. Listeria monocytogenes can grow and thrive at room temperature as well as refrigeration temperatures. A combination of antimicrobial agents provides a larger spectrum of listeriostatic and listeriocidal activity resulting in a more effective approach toward the control of L. monocytogenes. In this study, we evaluated the efficacy of 3 Food and Drug Administration-approved generally recognized as safe (GRAS) antimicrobials, nisin (NIS), lauric arginate ethyl ester (LAE), and ε-polylysine (EPL), and the endolysin PlyP100 individually and in combination for control of L. monocytogenes in QF at 4°C, 7°C, and 10°C. Additionally, growth curves of L. monocytogenes were obtained in BHI broth and QF at these temperatures. In order for an antimicrobial to be considered a postlethality treatment for L. monocytogenes, it should not allow an increase of more than 2-log over the product's shelf life. Three treatments, PlyP100, PlyP100 + NIS, and EPL + LAE, effectively kept the pathogen below the 2 log growth threshold at 4°C. However, at 7°C and 10°C, none of the antimicrobial treatments could inhibit L. monocytogenes growth (i.e., <2 log). Overall, our results suggest the importance of considering the effect of cold storage temperatures above 4°C on the antilisterial efficacy of antimicrobial treatments in QF.

The Strange Case of Prevotella copri: Dr. Jekyll or Mr. Hyde?

We report a rare case of Staphylococcus lugdunensis (S. lugdunensis) endocarditis in a 42-year-old male with a bicuspid aortic valve and an ascending aortic aneurysm. The patient initially presented with upper respiratory symptoms but rapidly deteriorated, developing acute pulmonary edema. Transthoracic and transesophageal echocardiography demonstrated severe aortic regurgitation, vegetation on the bicuspid valve, and a 52-mm ascending aortic aneurysm. Intraoperative assessment revealed extensive destruction involving the mitral–aortic intervalvular fibrosa (MAIVF), membranous septum, and anterior mitral leaflet. Emergency surgery was performed, including reconstruction of the MAIVF and membranous septum, mechanical aortic valve replacement, and ascending aortic replacement via the Wheat procedure. Tissue and blood cultures grew S. lugdunensis, which was sensitive to vancomycin. The patient completed a six-week antibiotic regimen and was discharged in stable condition. This case highlights a unique association between S. lugdunensis endocarditis and focal MAIVF destruction in bicuspid aortic valve disease, underscoring the importance of timely surgical intervention.

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Three-dimensional echocardiography (3DE), via both transthoracic and transoesophageal approaches, has become an essential tool in the assessment of mitral valve (MV) disease, providing detailed anatomical and functional insights fundamental to both diagnosis and therapeutic planning. By offering a unique volumetric perspective, 3DE allows a comprehensive visualization of the entire MV apparatus, enhancing the capacity to appreciate anatomical and functional details.In mitral regurgitation (MR), 3DE adds pivotal information about leaflet morphology, annular geometry, and sub-valvular structures across all Carpentier subtypes, playing a central role in surgical and percutaneous procedural planning. 3D colour-mode imaging improves spatial localization of regurgitant jets and enables advanced MR quantification techniques. Specifically, 3D proximal isovelocity surface area and 3D vena contracta area offer improved accuracy over 2D methods, particularly in functional MR, and in multiple or complex jets. Additionally, the 3D indirect volumetric method and emerging semi-automated software are further tools for MR quantification. In mitral stenosis, 3D planimetry via transthoracic and transoesophageal echocardiography provides more accurate and reproducible measurements of the MV area compared with 2D, especially in challenging anatomies or suboptimal imaging planes. 3DE, especially using the transoesophageal approach, also improves commissural evaluation, which is essential for patient selection for percutaneous valvuloplasty. Overall, 3DE has redefined MV imaging by offering unparalleled anatomical and quantitative assessment. Its integration into routine clinical practice is critical for modern echocardiography and should be considered a core competency for cardiovascular imaging specialists.